Electric brush



Patented Oct. 11, 1921.

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ATTORNEY w. E. scHwAnzMANN. ELECTRIC BRUSH.

APPLICATION FILED FEB. I4, 192i. 1,393,704.

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l ployed in a WOLFGANG E. SCHWARZMANN, 0F

LONGMEADOW, MASSACHUSETTS, ASSIGNOR T0 AMERICAN BOSCH MAGNETO CORPORATION, OF SPRINGFIELD, MASSACHUSETTS,

A CORPORATION 0F NEW YORK.

ELECTRIC BRUSH.

Specification of Letters Patent.

Patented Oct. 11, 1921.

Application led February 14, 1921. Serial No. 444,715.

To all whom t may concern:

Be it known that v I, WOLFGANG SCHWARZMANN, a citizen 4of the United States, residing at Longmeadow, 1n the county of Hampden, State of Massachusetts, have invented certain new and useful Improvements in Electric Brushes; and I do hereby declare the following to be a full, clear, andexact description of the invention, such as will enable others skilled inthe art to which it appertains to make and use the same. g

The present invention relates to ignition systems and has particular reference to contact brush devices such as those that are used in the center post of a distributer or the electrode cap of a collector for amagneto or other parts making use of contact brushes 1n 1gn1- tion systems.

In devices of this type heretofore in use, whether or not the contact brushr be emdistributer cap, or a distributer rotor, or in connection with a collector on a magneto or otherwise, the brush was usually made of carbon and slidable in a recess of an insert or guide member and was usually connected to an end of a coil spring located within the inner portion of such recess, so that upon the removal ofthe cap for inspection of the internal arts -of the mechanism covered thereby, the rush would be moved outwardly by such spring. The total projection of such brush fromits guide member or insert, however, has been prevented by cutting away a side portion of the brush so as to form a shoulder thereon intermediate the ends thereof and by also attaching a hook on the insert with the end of the hook extending in the path of the shoulder so that as the brush was moved outwardly by the spring, the shoulder would contact with the end ofthe hook, such hookend thus limiting the outward movement of the brush. In other similar devices, the brush has been provided with a cross pin, the ends of which were capable of having a limited sliding movement in elongated slots formed in the sides of the insert, or by having an elongated slot in the brush with a cross pin extendingr through such slot and fixed to the sides of the insert. In such structures, however, after the brush and the hook or cross pin were assembled, the brush was permanently held in the recess of the insert and could not be readily removed or replaced in the event of the brush becoming worn, broken or otherwise defective and inoperative. It is, therefore, an object of my invention to construct a contact brush device preventing the total outwardmovement of the brush but permitting its ready removal and replacement when desired, and to also construct the device so as to avoid the breaking of the carbon brush as well as for making the device strong, durable, efficient in operation and low in cost of construction.

It is, therefore, a part of the invention to construct a contact brush device Iwith a guide member having a recess in which a brush is slidably located, vsuch brush being preferably carried by a holder which is slidable in such recess, the holder having a recess in one of its ends and the brush being permanently fastened to such holder in the recess thereof, a resilientv means, such as a spring, being located in the recess of the guide member and adapted to move the holder and brush outwardly. Coperative with the brush and holder is a detachable means for limiting the outward movement of the holder and brush, such means preferably comprising a shoulder on the holder, intermediate the ends thereof, a groove of preferably annular form being provided in the guide member and a detachable member, the latter being preferably expansible and in the form of a ring and adapted to expand into such groove, so as to coperate with such shoulder on the holder. The holder preferably has a portion, intermediate its ends, of arger diameter than its end portions, the enlarged portion thus presenting shoulders, one for the engagement with the expansible ring and the other for the engagement of the spring which preferably surrounds one of the end portions of the holder. The other end of the guide member has means for the connection of a` lead terminal for the purpose of receiving and conducting electrical current to the brush and holder from such lead.

In the accompanying drawing illustrating a preferred form of the invention, preferably shown in use with a distributor:

Figure l is a side elevation partly in section of a distributor cap embodying the invention; Fig. 2 is a detail view of a spring used in connection with the contact brush; Fig. 3 is a view in elevation and partly 1n section of the brush and holder; and Fig. 4 is a top plan view of an expanding ring used for limiting the outward movement of the holder and brush.

Referring more particularly to the draw ing, the invention is embodied in a distributer l having a distributer cap 2 surmounted by a series ol lead posts 3 and a center post 4 to which is connected the lead terminal from the secondary winding of a magneto or induction coil. rl`he distributer`cap, comprisingthe postsand 4, is usually made of suitable insulating material such as bakelite or `similar compositions, and in accordance with my invention, l Vconstruct the center post of the distributor cap ci moldable material and with member 5, preferably ci' cylindrical form, having a knurled surface, and permanently secured or fastened in position within the post 4 at the time or" molding the distributer cap, by providing `the insert 5 with' recesses or an annular groove 6 within which projects an integral molded portion 7 of the post 4 so that the.- insert 5 will remain in ixed position. Both ends of this insert or guide member are provided with substantially cylindrical recesses Sand 9., the recess 9, near its opened end being threaded to receive a threaded plug lll., the latter being centrally bored for the passage oir' the conducting wire or wires of a lead l2 connected to the seconda@v winding or" an induction coil or magnete armature. PThe end or ends i3 ol the conducting portion of the `read l2 projects beyond the member i0 into the bottom of the recess il so that when the of the plug l() will compress the ends 13 ai the conductor into the lower portion of the recess 9, thus making contact with the ril metal. oi' the insert or guide member 5 and the conducting portion ci' the lead. rThe post 4 may be surmour by i5, as in :he usual manner, the ad or the plug l being molded in with ne cap 'i5 in the case or the insert in t ln the lower or inner fe f; 4 is slidably mounted t ing an intermediate no1" larger diameter than the end por r s i7 and 18 thereof, so that the ends of the 5 rermediate portion 'i6 provides shoulders and 20, respectively, the purpose of which is hereinafter more fully described. The end portion i7 has a recess 21 in which is located a carbon brush or contact piece 22, the latter being preferably tapered or conical at its outer end and projecting outwardly from the recess 21, the outer end portion 23 of the holder end por- Ition 17 being tapered and compressed inwardly or spun over the tapered surface 24 of the carbon contact 22 so as to permanently `nold or fasten the contact 22 into place in the recess 2l of the holder. At the inner parts carried thereby,

a metal insert or guide plug l0 is screwed into place, the lower end f portion of the recess 8 is located a coil spring 25 with one end reacting against the shoulder of the holder and the other end against the bottom of the recess 8, the spring continually tending to move the holder, and the outwardly, as will be apparentfrom the view illustrated in Fig. l of the drawing. Near the opened end of the recess 8 the insert or guide member has an inner annular groove'26 in which is positioned or expanded an expansible ring 27, this ring being preferably made from a piece of steelwire bent in the form of an annulus and cut or parted along a radius of thel annulus so as to permit contraction and expansionvthereof, as is clearly shown in Fig. 4 of the drawing.

lt will be observed that the ring 27 is so located that as the holder, carrying the brush 22, is moved outwardly by the spring 25, when the distributer cap 2 is removed, the shoulder i9 of the holder will contact with the ring 27 and further outward inove ment of the holder is thus arrested, thus preventing the projection of the outer end of the brush and the holder to such extent as to render it possible of breaking it by contact with any of the projecting parts of the distributer when the distributer cap is being removed from or inserted into place upon the.

distributor housing or casing' 28. `Within the distributer housing 28 is rotatably supported, in the usual manner, a distributer rotor 29 'in which is embedded a metal or conducting insert 30 usually disposed ra i.

dially and coperative, l.in a well known manner, with. contact pieces located in the posts 3, the latter having leads 3l connected at the other ends thereof to the spark plugs in an internal combustion engine.

ln use, when the distributer cap 2 is removed, the spring 25 will move the holder, and the brush 22 carried thereby, outwardly until the shoulder' 19 contacts with the ring 27, further movement being thus prevented. lt will thus be observed that the brush will not project a great distance from the cap 2. 'Upon replacing the cap upon the housing 2S, should the brush 24 contact with any projecting element within the distributor out ci the socket or recess found within the insert 5, and, accordingly. the brush will not be made inoperative as in the old type o devices. As the cap is moved into proper position the brush 24 will contact with the conducting plate or insert 30, the spring 25 compressed and the holder and the brush caused to move inwardly along the recess 28, into the operative position of the device, as is shown in Fig. l of the drawing.A

If it be desired to remove the holder and brush entirely from the insert 5, the ring 27 may be contracted or compressed so that it may be readily removed Jfrom the groove lllti 1,393,704 y i l 26, and the holder, with the brush and the spring 25, mayfbe bodily removed.

It will also be apparent that in assembling the parts the spring is irst inserted in the recess 8 andthe holder next inserted, and then the ring 27, which while in contracted form, is placed into the opening of the recess 8 and permitted to expand into the groove v26. It will be thus noted from the above that the assembling and the replacing ofthe parts are readily and conveniently made.

Havmg thus described my invention what I caim 1s:

l. A contact brush device comprising a,

guide member having a recess, a brush slidable in said recess, resilient means for progressively moving said brush4 outwardly when it wears, and a detachable means constructed and arranged to permit progressive movement of said brush and coperative with said brush to limit the maximum out- -ward movementlthereof, whereby upon reguide member having a recess, a brush hoider having a recess in an end thereof and siidn able in said recess of said guide member, a brush permanently fastened to said hoider in said recess thereof, resiiient means for mov ing said holder outwardly, and detachable means coperative with said holder to limit the outward movement thereof, whereby upon removing said detachable means, said holder and brush may be removed from said recess of said member.

4. An ignition Contact brush device com` prising a'guide member having a recess, a brush holder having a recess in an end thereof and having a shoui" er intermediate 'the ends thereof, said holder being siidable in said recess of said member, a brush permanently fastened to said holder in said recess thereof, resilientmeans for moving said holder outwardly, and detachable means cooperative with said shoulder on said holder to iiinit the outward movement thereof, whereby upon removing said detachable means saidholder and brush may be removed from said recess of said member.

5. A contact brush device comprising a guide mem er having a recess, a brush siidable in sai recess, resilient means for progressively moving said brush outwardly when it wears, a detachable member constructed and arranged in said recess to permit progressive movement of said brush, and coperative with said brush to iimit the maximum outward v movement thereof, whereby upon removing said detachable member, said brush may be removed from said recess.

6. .ein ignition cont-act brush device comprising a guide member having a recess, a brushl slidable in said recess, resilient means for moving said brush outwardly, an es:o pansible detachable member in said recess and coperative with said brush to limit the outward movement thereof, whereby upon contracting and removing said detachable member, said brush may be removed from said recess.

7. A contact brush device,` guidemember having a recess provided with an annular groove, a brush slldabie in said recess, resilient means for moving said brush outwardly, an eapansible detachabie member in said groove and co erative with said brush to limit the outwar movement there of, whereby'upon contracting and removing said detachable member, said brush may be removed from said recess.

8. [in ignition contact brush Adevice com prising a guide member having a recess pron vided with an annular groove, a brush siidable in said recess, resilient means for movn ing said brush outwardly, an expansible de tachable ring expanded into said groove and cooperative with said brush to limit the outward movement thereof, whereby upon conn tracting and removing said ring, said brush may be removed from said recess.

9. A contact brush device comprising a comprising a 'guide .member having a recess in an end thereof and. having means at the other end thereof for the connection of a lead tei"- minai, a brush holder having an interino diate portion of larger diameter than the end portions thereof for providing shoulders at each end of said intermediate portion,

.said intermediate portion being slidable in said recess of said guide member, one of said end portlo'ns having -a recess, a carbon brush fastened in 'said recess of said holder, a

holder, whereby upon contracting and removing said ring, -said brush may be removed from said recess.

In testimony WhereofIaiiiX my signature.

' WOLFGANG E. SCHWARZMANN. 

